Grinding machine



Oct. 29, 1929. F. M. KERN ET AL 1,733,492

GRINDING momma Original Filed-March 3, 1926 2 Sheets-Sheet l 4+ 7 4-5 sa 4 5 E Z i? 1 HA 2a 1H gwoentolz JredMHern 44! f Ernest fifieumrd Oct. 29, 1929. KERN Er AL 1,733,492

GRINDING MACHINE Original Filed March 3, 1926 2 Sheets-Sheet 2 Jred M. He rn l I I E H 2 I Ernest fifieward Patented 0a. 29, 1929 UNITED STATES PATENT OFFICE FRED M. KERN AND ERNEST R. SEWARD, OF DETROIT, MICHIGAN, ASSIGNORS, BY GRINDERS INCORPORATED, OF CINCINNATI.

*MESNE ASSIGNMENTS, TO CINCINNATI OHIO, A CORPORATION OF OHIO GRINDING MACHINE Application filed March 3, 1926, Serial No. 91,861. Renewed March 1, 1929.

This invention relates to grinding machines, and more particularly to centerless grinding machines in which a work iece is rotated and ground between a rapi ly ro tated grinding wheel and a slowly rotated work regulating wheel. v

In grinding cylindrical work in a centerless grinding machine wherein the work is rotated and ground between a rapidly rotated grinding wheel and a slowly rotated work regulating wheel, it is important, if precision grinding is to be achieved, that the work be properly positioned between the wheels. This is usually accomplished by means of one or more work holding members, such as a work holding member or blade which is positioned in the machine with its operative surface or edge parallel with the line of contact of the work and grinding wheel when a grinding wheel of the peripheral type is employed. In most cases, the adjustment of such a work holding member has been made manually by a guess and try method and required considerable time of a skilled mechanic, and even then the adjustment often was not made as accurately as might be desired.

One of the objectsof this invention is to provide a grinding machine having a practical and thoroughly efiicient means for adjusting the position of a work holding member.

It is another object of the invention to provide an improved precision adjusting mechanism in a centerless grinding machine for readily, conveniently, and accurately adjusting a work holding member or blade by moving it through successive parallel positions in a plane passing through the work;

In grinding machines wherein the work regulating wheel is carried by a vertically movable column, some dif ficulty has been experienced at times in properly adjusting the blade after moving the work regulating wheel to a proper grinding position relative to the grinding wheel or after having trued the grinding wheel. In such former constructions, the blades were held in a bracket mounted on the frame of the machine and when the work regulating wheel was moved elements, and

toward the grinding wheel, after truing the latter, it was also moved nearer the blade. As a result, after continued truing of the grinding wheel, the work regulating wheel was brought closer and closer to the blade and finally came in contact therewith causing trouble.

It is a further object of the present invention to provide certain improvements in a centerless grindin machine whereby the work holding mem er or members or blades are mounted in such a manner as to move simultaneously with and an amount equal to any displacement of the regulating wheel.

Another object is to provide mechanism of the above nature which is of simple and compact construction. Other objects will be in part obvious or in part pointed out hereinafter. v

The invention accordingly consists in the features of construction, combinations of arrangements of parts as will be exemplified in the structure to be hereinafter described and the scope of the application of which will be indicated in the following claims.

In the accompanying drawings, in which are shown one or more of the various possible embodiments of the features of this invention,

Figure 1 is a side elevational view, partly broken away, of a centerless grinding machine embodying the invention;

Fig. 2 is a detail view of the precision adjusting mechanism for moving the rear guide blade;

Fig. 8 is a front elevational View of a portion of the machine of Fig. 1 showing the mounting for the regulating wheel; and

Fig. 4 is a detail view of a modification of the adjusting mechanism.

Similar reference characters refer to similar parts throughout the several views of the drawings.

In the drawing I have illustrated one type of centerless grinding machine embodying the invention in which the work regulating wheel is set at an angle to the grinding wheel so as to propel the work axially past the grinding wheel. It will be understood that the invention is not limited to this particular type of machine and that certain features of the invention and modifications thereof may be embodied in any of the various types of centerless grinding machines including those particularly adapted for grinding shouldered work. The machine illustrated comprises a frame 10 in which a grinding wheel spindle 11 carrying a grinding wheel 12 is mounted for rapid rotation in suitable bearings (not shown). The grinding wheel 12 is rotated rapidly, in the direction indicated by the ar row in Fig. 1, from any appropriate source of power by means of a belt 13 passing over the pulley 14 secured upon the spindle 11. A column 15, which is mounted for vertical movement in a cylindrical portion 16 of the frame 10, is prevented from turning by means of a key 17 in the frame engaging a slot 18 in the column, and may be moved up and down by means of a hand wheel (not shown) on a shaft 19 carrying a worm 20 which engages a worm wheel 21 secured upon a screw shaft 22. The shaft '22 is mounted in the column 15 for rotation and against axial movement relative thereto, and is adapted to engage the threaded portion of a boss 23 integral with the frame 10. A water pan 24 and a regulating wheel support 25 are secured together to turn about a pivot 26 and are adjustably mounted upon the column 15 by means of bolts 27 passing through arcuated slots 28 (Fig. 3) in the column. Suitable bearings (not shown) are provided within the bearing casing 29 for rotatably mounting a spindle30 carrying a work regulating wheel 31 which is rotated relatively slow, in the direction indicated by the arrow in Fig. 1 for example, by means of a motor 32 connected therewith by a shaft33 which projects upwardly through an opening 34 in the water pan 24 into a housing 35 and carries a worm 36-engaging a worm wheel 37 on the spindle An upwardly extending bracket 40 is secured to a projection 41 near the top of the column 15 by'means of bolts 42, and is proshaft 47. The rack 45 is provided'with a horizontally extending arm 48 having a groove 49 for engaging a tongue 50 upon a bracket 51 which is adjustably mounted on the rack by means of a bolt 52 passing through a slot 53 in the bracket 51. A front blade 55 is held in the bracket 51 by means of bolts 56. At least one of the work holding members or blades is preferably mounted so that it may be adjusted accurately and conveniently by a mechanism adapted to move the member to parallel positions in a plane passing through the work. Thus; in the machine illustrated, the work w rests upon the regulating wheel 31 between the front blade 55 and a rear blade 57 (Figs. 1 and 2) which latter is held by bolts 58 passing through slots 59 in a horizontally extending arm 60 on the rack 45. A preferred mechanism for finely adjusting the blade 57 includes a pair of cams 61 secured upon a rotatably mounted shaft 62 and each of which is adapted tocontact with one end a pin 63 slidably mounted in the rack 45, the other end engaging the rear of the blade 57 For grinding cylindrical workinamachine of this type the axis of the work regulating wheel 31 is skewed relative to the axis of the grinding wheel 12 by unloosening the bolts 27 and turning the water pan 24, which turns the work regulating wheel support 25. The regulating wheel 31 is then moved upward to an appropriate position for grinding the particular size of work desired, by turning a hand wheel (not shown) upon the shaft 19. The front blade 55 is then brought to a proper position by unloosening the bolt 52 and'moving the bracket 51. The rear blade 57 is finely adjusted by unloosening the bolts 58 and turning the shaft 62 and conseqently the pair of cams 61 to move the blade into an appropriate position for precision grinding. If necessary, the blades may be adjusted vertically by turning the shaft 47 carrying the pinion 46which moves the rack 45 up and down. The grinding wheel 12 is then rotated rapidly, in the direction of the arrow in Fig. 1, from any appropriate source of power through the belt 13. The work regulating wheel is rotated relatively slowly, in the direction indicated by, the arrow in Fig. 1, by energizing the motor 32. The work to then enters between the wheels and is ground, and

is subesquently discharged by being propelled axially between the wheels on account of the relative positions of the axes of the grinding and work regulating wheels, or on account of the inclination between the path of travel of the operative surface of the regulating wheel and the path of travel'of the work.

A modification of the mechanism for finely adjusting the blade 57 is illustrated in Fig. 4. As there shown, each of a pair of screw shafts :65 is-mounted at one end in threaded holes 66 and secured at the other end to a rod 67 slidably and rotatably mounted in the rack 45 so as to engage the rearof the blade 57. A worm or spiral gear 68 is secured upon each shaft 65 for operative engagement with similar gears 69 secured upon a shaft 70 rotatably mounted in the rack. As the shaft 70 is turned the gears 68 and shafts 65 are rotated to move each of the rods 67 towards or away from the blade 57, and thus control the position of the latter when the bolts 58 are loosened.

A centerless grinding machine constructed in accordance with the features of the invention has been found to improve the character of the grinding and minimize the difiiculties heretofore encountered in centerless grinding, and greatly reduces the time required for, and increases the accuracy and ease of making necessary adjustments. The workholding member or blade 57 may be quickly adjusted accurately to a desired position for grinding whenever a new adjustment is required because of a change made by truing the grinding wheel or on account of grinding work of a difierent diameter.

The terms regulating wheel and slowly rotated regulating wheel are to be construed in the now commonly accepted understanding of those skilled in the centerless grinding art. The speeds of both the grinding wheel and the regulating wheel are preferably varied in accordance with the type and nature of the work to be ground as well as the particular operation to be performed. The grinding wheel is to be rotated at a speed found suitable for grinding the work and the regulating wheel is to be given such a speed that the work will rotate during the grinding operation at that rate which is found desirable for the particular operation to be performed. Without reference to the theory of operation, the regulating wheel serves to control the speed of the work and the work may be given a faster or slower speed by increasing or decreasing the speed of the regulating wheel respectively; by speed of the work is meant the speed of rotation of the work.

As many possible embodiments may be made of the above invention and as many changes might be made in the embodiment above set forth, it is to be understood that all matter hereinbefore set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is: j

1. A grinding machine comprising a grinding wheel and a work regulating wheel, a work holding member therebetween, a precision adjusting mechanism adapted to exert a plurality of equal forces simultaneously upon said member to move the same to successive parallel positions in a plane passing through the work between the wheels and means for rotating the grinding wheel rapidly to grind the work and the work regulating wheel slowly to rotate the work.

2. A grinding machine comprising a grinding wheel and a work regulating wheel, a blade for holding work therebetween, a plurality of movable members adapted to move the blade to successive parallel positions in a plane passing through the work between the wheels, means for moving said members equal distances simultaneously, and means for rotating the grinding wheel rapidly to grind the work and the work regulating wheel slowly to rotate the work.

3. A grinding machine comprising a grindin. wheel and a work regulating wheel. a blade for holding work therebetween, a plurality of movable members engaging the edge of the blade remote from the edge thereof engaged by the work, means for moving said members simultaneously equal distances to move the blade to successive parallel positions and means for rotating the grinding wheel rapidly and the work regulating wheel slowly to respectively grind and rotate the work.

4. A grinding machine comprising a grinding wheel, a member adapted for maintaining the work in operative contact with the grinding wheel, a cam controlled adjusting mechanism for moving said member to successive parallel positions in a plane'passing through the work and means for rotating the grinding wheel rapidly to grind the work.

5. A grinding machine comprising a grinding wheel, a support movable relative to the grinding wheel, a work regulating wheel mounted thereon peripherally opposed to the grinding wheel, a work holding member mounted on said support for maintaining work in a grinding position between the wheels, a precision adjusting mechanism for moving said member through successive parallel positions in a plane passing through the work and means for rotating the grind ing wheel rapidly and the work regulating wheel slowly to respectively grind and rotate the work.

6. A grinding machine comprising a grinding wheel, a vertically movable column below the grinding wheel, a work regulating wheel mounted thereon for rotating work in rotative contact with the grinding wheel, a work holding member for guiding work between the wheels, a precision adjusting mechanism for moving said member horizontally through successive positions parallel to the axis of the grinding wheel and means for rotating the grinding Wheel rapidly to grind the work and the work regulating wheel slowly to rotate the work.

7. A grinding machine comprising a rapidly rotated grinding wheel, a vertically movable column below the grinding wheel, a slowly rotated work regulating wheel mounted thereon for rotating work in rotative contact with the grinding wheel, a work holding member adjustably mounted between the wheels and means for moving the Work regulating wheel and said member simultaneously into a grinding position.

8. A grinding machine comprising a grind-.

ing wheel, a vertically movable column below the grinding wheel, a work regulating wheel adjustably mounted thereon so that its axis may be skewed relativeto the axis of the grinding wheel, a blade mounted on the column for holding work between the wheels, a precision adjusting mechanism adapted to move said blade through successive horizontal positions parallel to the axis of the grinding wheel and means for rotating the grinding Wheel rapidly and the work regulating wheel slowly to respectively grind and rotate the work.

9. In a grinding machine, in combination, a grinding wheel, a regulating wheel, a work supporting member between said wheels, and means for adjusting the position of said member including a rotatable. shaft, a plurality of cams mounted upon said shaft connected to act against a plurality of different portions of said member, and means for rotating said shaft. I

10. In a grinding machine, in combination, a grinding wheel, a re ulating wheel, a support upon which one 0 said wheels is mounted and which is movable toward and away from the other of said wheels, means for moving said support, a bracket mountedupon said support, and a work holding member mounted upon said bracket and projecting between the wheels and adjustable in position upon said bracket in a direction transverse to the direction of movement of said support.

11. In a grinding machine, in combination, a grinding wheel, a regulating wheel, a support upon which one of said wheels is mounted and which is movable, toward and away from the other of said wheels, means for moving said support, a bracket mounted upon said support for adjustment in position thereon in .a direction substantially lengthwise of the direction of movement of said support, and a work holding member mounted upon said bracket and projecting between said wheels.

12. In a grinding machine, in combination, a grinding wheel, a regulating wheel, asupport upon which one of said wheels is mounted and which is movable toward and away from the other of said wheels, means for moving said support, a bracket mounted upon said support for adjustment in position thereon in a direction substantially lengthwise of the direction of movement of said support, a work holding member mounted upon said bracket and projecting between said wheels, and means for adjusting the position of said work holding member upon said bracket in a direction substantially transverse to the direction of movement of said support.

13. In a grinding machine, in combination, a grinding wheel, a regulating wheel, a support upon which one of said wheels is mounted and which is movable toward and away from the other of said wheels, means for moving said support, a bracket mounted upon said support for adjustment in position thereon in a direction substantially lengthwise of the direction of movement of said 

